A typical asphalt roofing shingle has a buttlap portion, which is the exposed surface visible on a roof, and a headlap portion, which is secured to the roof by glue or nails or other appropriate securing means. Shingles of this type are generally installed on a roof by working up the roof from the edge to the peak, the headlap portion of each shingle being covered by the buttlap portions of the next course of installed shingles.
The most popular asphalt shingles fall into three different categories: strip, three-tab and laminated. FIG. 1A depicts the simplest of the three types, a strip shingle. The strip shingle 3 has a headlap portion 8 and a buttlap portion 5. The phantom lines of the figure indicate the position of the course of shingles installed over the shingle 3.
FIG. 1B depicts a typical three-tab shingle 12 with headlap portion 18 and buttlap portion 15. The three-tab shingle is so called because the buttlap portion is divided into three tabs 21, 24 and 27 such that, when the overlying course of shingles is installed, the exposed buttlap portion appears as three smaller individual shingles. The phantom lines of FIG. 1B indicate the position of the course of shingles installed over the shingle 12.
FIG. 1C depicts a laminated shingle with headlap portion 33 and buttlap portion 36. A laminated shingle differs from the strip and three-tab shingles in that the laminated shingle is a two-ply construction wherein the tabs 39, 42 and 45 of an overlay ply are spaced relatively far apart and a backer strip 48, which is visible between the tabs, is adhered underneath. This gives a desirable thicker appearance to the shingle. The phantom lines of FIG. 1C indicate the position of the course of shingles installed over the shingle 30.
Each of the standard shingles depicted in FIGS. 1A, 1B and 1C also has a line of self-sealing adhesive patches 50 on the headlap portion. The adhesive provides a convenient means for sealing the leading edge of the next course of installed shingles, thereby assisting in preventing wind from getting under the buttlap portion and blowing the shingles off of the roof. The adhesive may be deposited on the shingle in any number of alternative ways, such as in a solid line or as dots across the headlap portion. This stick-down system has been known in the art for some time and is described in U.S. Pat. No. 4,559,267, the disclosure of which is incorporated herein by reference. In an alternative stick-down system, the self-sealing adhesive is placed near the leading edge of the underside of the buttlap portion of the shingle so that when the shingle is installed, the leading edge adheres to the headlap portion of the previous course of shingles.
Because there is no previous course of shingles, either with or without an adhesive material deposited thereon, present at the edge of the roof when a roofer starts to install shingles, roofers have typically engaged in the labor intensive and wasteful practice of trimming the buttlap portion from standard shingles and nailing down a headlap course at the edge of the roof. The shingles in this headlap course are sometimes referred to as starter shingles. The use of starter shingles is always necessary, even when shingles of the type having the adhesive on the underside of the buttlap portion are used, to ensure proper weatherproofing. After installing a course of starter shingles, the roofers can then lay down the first row of shingles, securing the buttlap portion to the trimmed shingles, and begin working up the roof. This type of starter shingle is the subject of U.S. Pat. No. 4,637,191, wherein a three-tab shingle, as described above with reference to FIG. 1B, is manufactured with perforations between the headlap and buttlap portions for ease of separation. The patent further discusses using the removed buttlap tab portions as shingling material elsewhere on the roof, e.g., near the peak as a "topping out" course of shingles in instances where standard ridge shingles do not bridge the gap between shingle courses on either side of the peak. The need for a "topping out" course of shingles, however, does not always arise. In addition, while the buttlap portion of a strip or three-tab shingle may find a use elsewhere on the roof, the two-ply construction of a laminated shingle buttlap portion does not lend itself to recycled use and would be wasted in all instances.
It is therefore an object of the present invention to eliminate the often wasteful practice of cutting away the buttlap portion of a shingle associated with providing a roofing starter strip. It is a further object of the present invention to provide a starter strip that may be used universally with any type roofing shingle, e.g., strip, three-tab and laminated.
For a better understanding of the present invention, together with other and further objects, reference is made to the following description, taken in conjunction with the accompanying drawings and its scope will be pointed out in the appended claims.